Switch mechanism



July 31, 1928;

J. H. KENDIG SWITCH MECHANISM Filed Dec. 7. 1921 2 Sheets-Sheet l f'iy.

W Y mm m e R W m N A H WITNESSES:

July 31, 1928. 1,678,862

J. H. KENDIG SWITCH MECHANISM Filed Dec. 7. 1921 2 Sheets-Sheet 2ATTORNEY INVENTOR ul/l/m/i He Patented July 31, 1928.

[UNITED STQAITESP-ATENT OFFICE.

JULIAN H. KENDIG, OI EDGEWQOD, ."E'ENNSYLVANIA, ASSIGNOR TO WESTINGHOUSEI ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA SWITCHMECHANISM.

Application filed December 7, 1921. Serial No. 520,568.

My invention relates to switch mechanism and particularly to switches ofthe rotatable snap-action type.

One object of my invention is to provide arotatable snap switch with acurrent-responsive element that causes the switch to be opened underoverload or short-circuit conditions in the circuit.

Another object of my invention is-to provide a switch, having the abovecharacteristics, whereinrotation of the switch-operating shaft toreclose the circuit resets the current-responsive device in condition toagain function inresponse to an overload or short-circuit.

Another object of my invention is to provide a snapswitch, having theabove characteristics, that is applicable to a three-pole circuit andwhich will open when an overtwo conductors of the circuit.

Another object of my invention is to provide a rotary snap switch with athermal cutout that is reset by a normal switch-closing operation andwhich may be repeatedly reset an indefinite number of times withoutrequiring attention.

Another object of my invention is to provide a rotary snap switch havinga thermal cutout which does not permit the circuit to be maintainedclosed should the switch be operated while the short-circuit or overloadconditions exist. w

Another object of my invention is to provide a rotary snap switch with asimple thermal-cutout mechanism that maybe installed in a case ofsimilar size'and shape to that of standard snap switches of equalcapacity.

These and other objects, that will be made apparent throughout thefurther description of the invention, are attained by means of theswitch mechanism hereinafter described, and illustrated in theaccompanying drawings, wherein: I

Figurel is a longitudinal sectional view of a rotatable snap switchembodying features of my invention;

Fig. 2 is a transverse section through the switch mechanism taken on theline 11-11 of Fig. 1, showing parts in section and in elevation;

Fig. 3 is a front view of the stop mechaload or a short-circuit occurson either or mechanlsm lncludes an lnsulatlng base 13,

nism for the switch, showing the operating shaft in transverse section;4

Fig. 4 is a side elevation'and end view of a cam member;

Figs. 5 and 6 are side and front elevational vlews, respectively, of acam-operating gear;

Figs. 7 and 8 are front and side elevational vlews of a stop member;

" REISSUED Fig. 9 is a transverse section through the I operating shaftshowing a ratchet device;

Figs 10 and 11 are front and side elevational views, respectively, of acurrent-responsive thermal element of the switch mechamsm;

Fig. 12 is a longitudinal section through a modified form of cutoutmechanism, and Fig. 13 is a transverse section through the mechanismshown in Fig. 12, the section bein taken on the line XII-XII of Fig. 12.Referring to the drawings, the switch preferably made of porcelain ormolded insulating compound, upon which an operating shaft 14 isrotatably mounted in a metal bearing bushing 15 which is provided with asquare plate 16. that is embedded in a square socket 17, molded in thebase. The bushing 15 is secured to the base by means of a threaded nut18. The inner end of the operating shaft extends beyond the bushing andis retained against longitudinal displacement in one direction by meansof a cotter pin 19. Upon the plate 16 a pawl 21 is pivoted, as indicatedin Fig. 9, for engaging a ratchet wheel 22 that is secured to i theshaft 14. The pawl 21 is normally retained in operative position withrespect to the ratchet wheel 22 by means of a leaf spring 23. The pawland ratchet serve to prevent counter-clockwise rotation of the operatingshaft for a reason that will hereinafter appear.

The base 1s prov1ded with perforations 24 through which the ends ofcurrent conmeans of screws 32 which serve to clamp a conductor plate 33to the base. A switchcontact member 34 is mounted upon a ledge 35 in thebase and is attached thereto in spaced relation to the plate 33 by meansof screws 36. The plate 33 and switch-contact member 34 serve to supporta wire-like conductor shaft 37 between the ends of which athermally-responsive element 38 is mounted for rotation underpredetermined conditions.

Thelement 38 comprises a pinion having teeth 39 whichare adapted to meshwith an operating gear to be hereinafter described. The element 38 ismounted upon a metal hub 41 with a cylindrical insulating sheath 42disposed therebetween which insulates the gear from the conductor shaft.The hub 41 is provided with an opening of larger diameter than theconductor 37 at its central portion for the purpose of retaining a smallquantity of solder or other material having a low fusion point. The gearis retained in its operative position upon the conductor 37 by means ofcollars 43.

The terminal 30 is provided with a contact member 44 that is secured tothe base by means of screws 45 and is diametrically 0pposite the contactmember 34. The circuit across the contact members is bridged by means ofa switch member 46 that comprises two flat elastic sheets of conductingmaterial, preferably copper, that are clamped together by means ofrivets 47 and mounted upon a switch-supporting plate 48 in spacedrelation thereto. The ends of the switch member 46 are curved in suchmanner that, when the switch member is rotated, the contacts 34 and 44split them and are yieldingly engaged thereby.

The switchmember is yieldingly connected to the operating shaft 14 bymeans of a helical spring 49 that is secured, at one end, to a notchedshoulder 51 on the operating shaft and, atthe other end, to theoperating plate 48. It will be seen from the foregoing that, when theoperating shaft, which is provided with an operating handle 52, isrotatedin a clockwise direction, the spring 49 will cause the switchmember to be similarly rotated.

In order to cause the switch to move with a snap-action from openposition, wherein the switch member is disposed at right angles to thecontact'members, to the closed position wherein. the ends of the switchmember yieldingiy engage the contact members, provision is made toprevent rotation of the switch memberuntil after the operating shaft hasbeen turned a predetermined distance. This action causes energy to bestored in the spring 49 which moves the switch member with a snap-actionwhen the said member is released. This is accomplished by means of awell known cam-operated latch-and-stop mechanism which includes a stopplate 53 that is provided with four projections or stop lugs 54 (seeFigs. l, 2,3, 7 and 8). The plate is supported upon the base by means ofwings 55 that are attached to the base by means of screws 56. A latch ortrigger 57, illustrated in Fig. 3, is mounted for rotation about theshaft '14 and is provided with a circular opening 58 into which aprojection 59 extends. The opening 58 is of such diameter that the latch57 may be moved transversely of the axis of the shaft 14 a sufficientdistance to withdraw the latch finger 61 from engagement with one of thestop lugs 54. A cam '62, that is adapted to be rotated by the shaft 14,operates in the opening 58. This cam comprises two semi-circularsections 63 and 64 of different diameters having their center ofcurvature disposed eccentric to the axis of the shaft 14. Thesemi-circular sections are so related that the ends of the larger formtwo contact projections 65 and 66.

Referring to Fig. 3, it will be seen that, when the cam 62 is rotated ina clockwise direction, the curved section 64 of the cam engages theprojection 59 and causes the latch 57 to be movedtransversely of theaxis of the shaft 14 until the finger 61 clears the stop 54. The latch57 is provided with an integral upstruck projection 67 that projectstoward the handle 52 and o erates in a radial slot 68 in the switc-supporting plate 48.

By reason of this construction, the latch 57 is caused to rotate withthe switch-sup porting plate 48, when thefinger 61 of the latch has beenmoved clear of the stop 54.

- The instant the finger 61 clears the stop, the

spring 49, which'has been wound by the turning movement of the operatingshaft 14, causes the switch-supporting plate and the switch member to berotated through with a snap-action into the open position wherein theswitch member is disposed at right angles to the contact members.

Rotary movement of the latch 57 with respect to the shaft 14and cam 62causes the latch or finger 61 to be moved outwardly radially during itsmovement so that it is again in position to engage the next succeedingstop 54 and to arrest the movement of the switch member in the openposition. By reason of this construction,'the switch may be movedalternately from open to closed position and from closed to openposition by turning the operating shaft in a clockwise direction.

The latch 57 is provided with a shoulder 69 which engages theinner face71 of the stop member 54 and prevents counter-clockwise rotation of thelatch 57. The projection 65 of the cam engages the projection 59 on thelatch and prevents rotation of the 81. A -spiral coil spring 82 tooperating shaft in a counter-clockwise direction. The projection 66 ofthe cam is ada ted to engage the projection 59 of the late and causepositive movement of the switch member in case the latter should adhereto the contact members. The switchoperating mechanism thus fardescribed, with the exception of the ratchet wheel 22 and pawl 21 whichserves as a ratchet mechanism, is well known in the art.

In the practice of my invention, I employ means to so rotate the cam 62,independently of the operating shaft, that the latch is moved toreleased position when the thermal-cutout mechanism is actuated by anoverload or short-circuit cond'tion in the circuit. To accomplish this,I provide the cam 62 with an integral ratchet sleeve 72 and also providethe cam slot 73 in which a pin 74, secured to the shaft 14, operates.

Referring to Fig 3, it will be seen that the pin 74 engages the end ofthe slot 73 and rotates the cam 62 with the shaft in a clockwisedirection. By reason of the arcuate slot 73, the cam may be rotatedindependently of the shaft 14 through at least 90. The purpose of thisprovision will hereinafter appear. A gear 75, illustrated in Figs. 1, 5and 6, is mounted for rotation upon the toothed portion of the ratchetsleeve 72 and is provided with a pawl 76 that is pivotally mounted in anarcuate slot 77 in the gear 75. The pawl is held in engagement with theratchet sleeve 72 by means of a leaf spring 78 that is secured in theslot 79 in .the gear 75. The pawl serves to permit a turnin movement ofthe shaft 14 in a cloclrwise direction independently of the gear 75 andalso serves to drive or turn theratchet sleeve and cam 62 in a-clockwisedirection when thegear 75 is turned in a similar d rection.

The gear,7 5 is provided, at its periphery, with teeth to mesh with theteeth of the pinion 38 of the thermal-responsive mechanism. Oneface ofthe gear 75 is provided with axially extendingteeth or projections iswound about the operating shaft and one end thereof is fixed to theshaft while the free end thereof extends outwardly and is provided witha bent portion 83 that is adapted to ratchet over the teeth 81 after thespring has been wound about the shaft a predetermined number of turnsand has stored therein a predetermined amount 'of energy. This springserves to drive or turn the gear 75 when the solder in the pin'on 38 hasbeen fused sufiiciently to release the pinion and to permit of freerotary movement thereof about the conductor 37. The gear 75 impartsrotary movement to the cam 62 and causes the latch 57 to release theswitch member which is then rotated to open posiwith an arcuate thecircuit, the switch tion by the spring 49. During this movement of theswitch member and cam, counter-clockwise movement of the operating shaftis prevented by the awl 21 which engages the teeth of'the rate et wheel22. The pawl 21 and ratchet wheel 22, at this t'me, perform the samefunction that the fingers of the operator perform during the turningmovement of the operating shaft when the switch is being manuallyoperated.

The spring 82 is supported between the washers 84 and 85 which retain itin operative position, the latter serving to enclose the pawl 21 and theratchet wheel 22.

Current normally flows from the conductor 25 through the terminal member29,

screws 32, conductor plate 33, conductor wire or shaft 37, contactmember 34, switch member 46, contact member 44, terminal 30 to theoppos'te conductor 25. It will be seen, therefore, that current, inpassing through the switch, flows through the conductor shaft 37 uponwhich the thermalresponsive device 38 is rotatably mounted. It isassumed that the spring 82 has sufficient energy stored therein torotate the, gear 75 and the cam 62 through not less than 1809. It isalso assumed that the spring 49 iswound with suflicient tension tooperate the switch member 46 through at least 180. During normal currentconditions in is actuated manually by turning the operating handle 52 ina clockwise direction through substantially 90 which'is sufficient torelease the switch member and normally cause the switch member to berotated through 90 from either open position to' closed position or fromclosed position to open position. After the switch member has been movedto closed position, sufficient energy still remains stored in the spring49 to cause the switch member to be rotated through 90. to open positionwhen has been released through the medium of the thermal-responsivemechanism.

-Assumng that the switch is in. closed position and that an overloadcondition occurs in the circuit, the solder'40 in the thermal-responsivedevice 38 is fused by the excess heat generated in the conductor shaft37 which permits of rotary movement of the gear 38. Heretofore, movementof the gear 75 had been revented by reason of the engagement of theteeth, thereof with the teeth of the gear 38 which has been heldstationary by the solder but the instant the ear 38 is released byreason of'the fusion of the solder, the spr'ng 82 causes the ear 75 toturn in a clockwise direction an to turn the cam 62 through the mediumof the pawl 76. which engages the teeth of the ratchet sleeve 72.Relative movement of the cam 62 with respect to the shaft 14, which is,at this time, held stationary by the the switch member reactive force ofthe spring 82, is permitted by reason of the arcuate slot 7 3. It willbe seen, therefore, that the instant the pinion of thethermal-responsive device 38 is released, the switch member will becaused to move to open position with a snap-action.

A short interval after the circuit is interrupted, the solder will resetor harden and again rigidly secure the pinion of the element 38 to theconductor 37 and prevent further rotation of the gear 75. Rotation ofthe operating handle and the shaft 14 in a clockwise direction through90 will cause the spring 82 to be rewound for the next operation andmove the pin 74: into driving engagement with the cam 62, after whichmovement of the operating handle through an additional 90 will cause theswitch member to be actuated to closed position wherein all of the partswill be in the relative positions occupied originally, and energy will2e stored in both springs 82 and 49, as beore.

Should overload or short-circuit conditions exist in the circuit whenthe switch is again closed, the pinion of the device 38 will again bereleased and cause the switch member to be moved to open position. ltis, therefore, impossible to maintain the circuit closed whileshort-circuit or overload conditions exist in the circuit.

Referring to Figs. 11 and 12, wherein a modified form ofthermal-responsive mechanism is illustrated, that is adapted for use ina multipole circuit, it will be seen that two separatethermal-responsive mechanisms are employed, the object being to providemechanism that will cause the switch to be moved to open position inresponse to overload or short-circuit conditions in either of twoconductors of a three conductor circuit.

In this construction, the switch mechanism is like that'previouslydescribed with the exception that the cam 62 is provided with a longerratchet sleeve 72 having two sets 86 and 87 of teeth disposed in spacedrelation. Two gears 88 and 89 that are similar to the gear 75pre-viously described and perform the same functionjare mounted forrotation about the sets of ratchet teeth 86 and 87, respectively. Eachis provided with a pawl 76 for engaging the teeth of the ratchetsections. The gears are of crown form having teeth 91 that extend in anaxial direction and which are adapted to mesh with thermal-responsivedevice pinions 92 and 93 that are rotatably mounted on conductor shafts95 and 94 of separate circuits. Between the gears, a planetary wheel 96is mounted for rotation about the sleeve 7 2. This wheel is providedwith axially extending teeth '97 over which a spiral coil spring 82ratchets in a manner similar to the spring 82, previously described. Thesleeve 72 is provided with an arcuate slot 98 which extends through 180.The inner end of the spring projects through the slot and extends to theshaft 14. It will be seen, therefore, that provision is made forpermitting the sleeve to rotate through at least 180 independently ofmovement of the spring 82.

Atdiametrically opposite points on the periphery of the wheel 96, a pairof planetary pinions 99 and 101 are pivotally mountbe released and thegear-meshed therewith will be permitted to be rotated. Rotation ofeither gear will cause the cam 62 to be moved to latch-releasingposition and cause opening movement of the switch. l Vhen one gear isreleased, the pinions 99 and 101 roll over the teeth of the stationarygear when the wheel 96 is turned by the spring and cause the moving gearto be moved through twice the angular distance of that through which thewheel 96 is turned. Should overload or short-circuit conditions occursimultaneously, or nearly simultaneously, in both conductors 9 1 and 95,the planetary pinions 99 will advance both the gears 88 and 89 throughat least 90 or suflicient distance to release the switch member andpermit it to be moved to open position. After the switch has been openedby reason of theoperation of the thermal-cut-out mechanism, it may bereset and the circuit again closed in a manner similar to that describedin connection with the single-pole switch.

While I have described and illustrated but two embodiments of myinvention, it will be apparent to those skilled in the art that variouschanges, modifications, substitutions, additions and omissions may bemade therein within the spirit and scope of my invention, as set forthin the appended claims.

I claim as'my invention:

- 1. The combination with a switch member adapted to be progressivelymoved to open and to closed positions with a snap-- action, and manuallyoperable means for arresting the switch member inpredeterminedpositions, of a thermal responsive means for actuating the manuallyoperable means for releasing the switch member.

2. The combination with a switch member adapted to be progressivelymoved to open and to closed positions with a snapaction, and manuallyoperable means for arresting the switch member in predeterminedpositions, of a current responsive means for actuating the manuallyoperable means for releasing the switch member.

3. The combination with a switch member adapted to be progressivelymoved to open and to closed positions with a snapaction, of manuallyoperable means for arresting the switch member in predeterminedpositions, of a thermal-responsive means for actuating the arrestingmeans.

4. The combination with a contact member, a progressively movable switchmember and manually operable means for arresting movement of the switchmember in predetermined positions with respect to the contact member, ofa thermal-responsive element for controlling the said arresting means.

5. The combination with a contact member, a progressively movable switchmember and manually releasable means for arresting movement of theswitch member in predetermined positions with respect to the contactmember, of a current-responsive element for controlling the saidarresting means. i

6. The combination with a contact member, a progressively movable switchmember and means for arresting movement of the switch member inpredetermined positions with respect to. the contact member, of afusible element for controlling the said arresting means. 7. Thecombination with a contact member, a progressively rotatable switchmember for alternately engaging and disengaging the contact member,energystoring means for rotating the switch in. one direction andmanually operable means for arresting movement of-the switch member inpredetermined positions'with respect to the contact member and forreleasifig'theswitch member when actuated, of acurrent-responsivemeansfor actuating the said arresting means. I

8. The combination with a contact-member, a rotatable switch member,energystoring means for rotating the switch member in one direction,means ;.for' actuating the energy-storing means rotatable in the samedirection as the switch. member, and manually operable means forarresting movement of the switch member in predetermined positions withrespect to the contact member. and for releasing thefswitch member, ofacurrentresponsive means for controlling movement of the sa d arresting-means.

Y 9. The combination with a contact mem- ,iber, a rotatable switchmember,,energy-storhing means for rotating the switch member in ne irs'wm, energystoring, means rotatable n the same .,direction astheswitchmember, andme'ans .actuated by the said ,actliatingjmeansfor arrestingmovement of the switch member;

in predetermined posltions with respect to the contact member, of acurrent-responsive ing the switch member. means for-actuating the.

by the operating member for engaging the stop member and arresting theswitch member in predetermined positions with respect to the switch, ofa current-responsive means for actuating the latch to releasing positionto permit movement of the switch member under predetermined currentconditions.

11. The combination with a contact member, a rotatable" progressivelymovable switch member for controlling a circuit and manually operablemeans for arresting movement of the switch member in predeterminedpositions with respect to the contact member and for releasing theswitch member when actuated, of a -means responsive to current in thecircuit for actuating the said arresting means.

12. The combination with a contact member, a switch member progressivelymovable in a predetermined path of movement to successively make andbreak engagement with the contact member, manually operable means forarresting movement of the switch member in predetermined positions inthe path of movement, means for biasing the switch member toward eachsuccessive position, of a current-responsive element for normallyretaining the switch member in a predetermined position against theactionof the biasing means and adapted to release the switch memberunder predetermined cursuccessive position, of a current-responsiveelement for normally retalning the swltch member in a predeterminedposition against the action of the biasing means and adapted to actuatethe manually operable means under] predetermined current conditions, anda manually-operable means for actuat- 14. The combination with a contactmember, a," switch f member progressively movable in apredetermined'path of movement to suc cessively make "and breakengagement with the contact" member, means for arresting movement of theswitch member in predetermined positions the path of movement,

means for biasing the switch member toward each successive position, ofmeans for normally retaining the switch member in a predeterminedposition against the action of the biasing means and adapted to releasethe switch member when actuated, and current responsive andmanually-operable means for actuating the retaining means forreleasingthe switch member.

15. In a switch mechanism, the combination with a contact member, arotatable switch member therefor, an operating shaft for the switchmember, a stop member, a latch forengaging the stop member and forarresting the switch member in predetermined positions with respect tothe contact member, a spring for connecting the operating shaft to theswitch member and for storing sufficient energy to move the switchmember from one position to another when the switch member is released,ameans actuated by the shaft for moving the latch to release position topermit movement of the switch member from one position to another, of ameans for preventing reverse movement of the shaft, an auxiliaryenergy-storing spring member actuated by the shaft for moving the latchmoving means to releasing position, and a current-responsive element forcontrolling the said sprmg member.

16. In a switchmechanism, the combination with a contact member, arotatable switch member therefor, an'operating shaft for the switchmember, a stop member, a latch for engaging the stop member and. forarresting the switch member in predetermined positions with respect tothe contact member, a spring for connecting the operating shaft to theswitch member and for storing suflicient energy to move the switchmember from one position to another when the switch member is released,a means actuated by the shaft for moving the latch to release positionto permit movement of the switch member from one position to another, ofa means for preventing reverse movement of the shaft, an auxiliary Venergy-storing spring member actuated by the shaft for moving the latchmoving means to releasing position independently of movement of theshaft and'a current responsive element for controlling the said springmember. p 17. In a switch mechanism, the combination with alatch-controlled rotatable snap switch having an energy-storing springnormally tending to advance the switch member from one operativeposition to another in response to movement of the switchoperating shaftto predetermined operative positions, of an auxiliary energy-storingmember actuated by movement of the shaft adapted to actuate the saidlatch to releasing position independently of movement of the shaft and acurrent-responsive element normally rendering the. auxiliaryenergystoring member inoperative and adapted to release the said elementunder predetermined current conditions.

18. In a switch mechanism, the combination with a contact member, arotatable switch member, an operating shaft rotatable in one directiononly, a sprmg for operatively connecting the shaft and the switch memberandrpermitting relative movement latch independently of the operatinghandle.

19. In a switch mechanism, the combination with a multipole switchhaving a plurality of separate switch elements for controlling aplurality of circuits and adapted to be moved from one operativeposition to another operative position, of a means normally tending tomove the switch elements from one position to another, means forreleasably retaining the switch elements in an operative position, andmeans responsive to current in any one of a plurality of circuitscontrolled by the switch elements for releasing the retaining meansunder prede-.

termined current conditions.

20; In a switch mechanism, the combination with a multipole switchhaving a plurality of separate switch elements for controlling aplurality of circuits and adapted to be moved from one operativeposition to another operative position, of a means nor,- mally tendingtomove the switch elements from one position to another, means forreleasably retaining the switch elements in an operative position, and afusible means responsive to current invanyione ofwa plurality ofcircuits controlled by the switch elements for releasing the retainingmeans under predetermined current conditions' 21. In a switch mechanism,the combination with a multipole switch having a plurality of separateswitch elements for controlling a plurality of circuits and adapted 'tobe moved from one operative position to another operative position, of'ameans normally tending to move the switch elements from one position toanother, means for releasably retaining the switch elements in anoperative position, a plurality of separate independentlyoperableelements for releasing the retaining means, and a current-respons-iveelement in each of the] plurality of circuits controlled by the switchelements for normally retaining the releasing means and for releasingthe said releasing means under predetermined current conditions.

22. In a switch mechanism, the combination with a multipole switchhaving a pluiii I I rality of separate switch elements for con- Itrolling a plurality of circuits and adapted leasably retaining theswitch elements in an operative position, a plurality of separateindependently operable elements for releasing the retaining means, asingle means for actuating the releasing elements and acurrent-responsive element in each of the plurality of circuitscontrolled by the switch elements for normally retaining each releasingmeans and for releasing the said retainmg means under predeterminedcurrent conditions.

23. In a switch mechanism, the combination with a multipole switchhaving a plurality of separate switch elements for controlling aplurality of circuits and adapted to be moved from one operativeposition to another operative position, of a means normally tending tomove the switch elements from. one position to another, means forreleasably retaining the switch elements in an operative position, aplurality of separate independently operable means, a single means foractuating the releasing elements and means responsive to current in anyone of' a plurality of circuits cont-rolled by the switch elements forpreventing operation of the releasing elements except under"predetermined current conditions.

24. In a switch mechanism, the combination with a multipole switchhaving a plurality of separate switch elements for controlling aplurality of circuits and adapted to be moved from one operativeposition to another operative position, of a means normally tending tomove the switch elements from one position to another, means forreleasably retaining the switch elements in an operative position, aplurality of independently operable gear members for actuating theretaining means to releasing position, a separate current-responsiveelement in separate circuits for preventing operation of the gearmembers except under predetermined current conditions and a planetarypinion for moving either gear member independently of, or simultaneouslywith, the other gear member.

25. Switch mechanism comprising a base, an operating shaft rotatablymounted thereon, ratchet means for preventing rotation of the operatingshaft except in one direction, contact members mountedon the base, aswitch member rotatably mounted on the operating shaft and movablerelatively thereto, a spring for, yieldingly connecting the shaft to theswitch member adapted to be biased by the operating shaft for moving theswitch member with a snap action when the switch member is released, astop member fixed to the base and'having a plurality of stop projectionsthereon for arresting movement of the switch member in predeterminedpositions with respect to the contact members, a latch member rotatablewith the switch member and movable into and out of engagement with thestop projections, a cam member having a lost-motion connection with theoperating shaft for actuating the latch members out of engagement with astop projection when the operating handle is rotated a predetermineddistance in opposition to the said opening, the said cam being providedwith a ratchet member, a gear mounted for rotation about the axis of theshaft and having a pawl engaging the ratchet member of the cam forrotating the cam independently of the shaft and provided with ratchetteeth, a spring for turning the said gear having one end attached totheshaft and having its free end extending into engagement with the ratchetteeth on the gear whereby the spring is wound to a predetermined pointwhen the shaft is rotated beyond a predetermined number of revolutions,a conductor connected to one of the contact members, and a pinionsecured thereto with fusible metal and meshing with the said gear forretaining the gear stationary and for releasing the gear underpredetermined current conditions.

26. Switch mechanism comprising a con tact member, a switch membermovable into engagement with the contact member, means including aprogressively rotatable shaft for operating the switch, and manuallyoperable and thermal-responsive means for releasably retaining theswitch in engagement with the contact member.

27. Switch mechanism comprising a contact member, a switch membermovable into engagement with the contact member, means including aprogressively rotatable shaft and a spring actuated by the shaft formoving the switch out of engagement with the contact member and manuallyoperable and thermal-responsive means for releasably retaining theswitch in engagement with the contact member.

28. Switch mechanism comprising a contact member, a switch membermovable into engagement with the contact member, means including aprogressively rotatable shaft for operating the switch, and manuallyoperable and current-responsive means for releasably retaining theswitch in engagement with the contact member. I

29. Switch mechanism comprising a contact member, a switch membermovable into engagement with the contact member, means including aprogressivel rotatable shaft and a spring actuated by t e shaft formoving the switch out of engagement with the contact member and manuallyoperable and taining the switch in engagement with the contact member.

30. Switch mechanism comprising a contact member, a switch member,movable into engagement with the contact member, means including aprogressively rotatable shaft for manually operating the switch member,resilient energy storing means placed under tension during manualoperation of the switch member for actuating the switch member andcurrent-responsive means continuously energized by the currenttraversing the switch member for liberating energy stored in theresilient means thereby causing interruption of the current traversingthe switch member under overload conditions. I

31. Switch mechanism comprising a switch member current-responsiveenergy storing means for initiating movement of the switch, aprogressively rotatable shaft for actuating the energy-storing means tostore energy therein, and a slip connection between the shaft and thesaid means whereby rotation of the shaftis permitted without furtheraffecting the said means after a predetermined amount of energy isstored therein.

32. Switch mechanism comprising a switch member, thermal-responsiveenergystoring means for initiating movement of the switch, aprogressively rotatable shaft for actuating the energy-storing means tostore energy therein, and a slip connection between the shaft and thesaid means whereby rotation of the shaft is permitted without furtheraffecting the said means after a predetermined amount of energy isstored therein.

In testimony whereof, I have hereunto subscribed my name this 8th day ofNovember, 1921.

JULIAN H. KENDIG.

